Cardiac Damage of the IFCC Background: The European Society of Cardiology/

mended that an increased cardiac troponin should be defined as a measurement above the 99th percentile value of the reference group. A total imprecision (CV) at the decision limit of <10 % is recommended. However, peer-reviewed data on assay imprecision are lacking. The purpose of this study was to construct the clinically relevant imprecision profiles for each of the commer-cially available cardiac troponin assays. Pools of human sera containing cardiac troponin concentrations around the MI decision limit were assessed to identify the lowest concentration associated with a 10 % CV. Methods: Eight serum pools targeting different concen-trations of cardiac troponin (I and T) were prepared and stored at 70 °C until usage. The cardiac troponin mea-surement protocol consisted of two replicates per spec-imen per run, and one run per day for 20 days, using two reagent lots and three calibrations. Manufacturers of each cardiac troponin assay directly performed the mea-surements. Data analysis for each assay was centralized and performed according to the NCCLS EP5-A guide-line. Results: The lowest concentrations (g/L) providing